[QUOTE= Another thing to keep in mind is feeding times to run time - some dogs are susceptable to bloat etc if they eat and exercise too close together.[/QUOTE]

Large chested dogs (Collies, Danes, German Shepherds, Rotts, etc.) should have a fairly empty stomach before running or any strenuous exercise. That means no meals within 4-6 hours of running. Bloat is a serious condition that can cause a painful death if the stomach twists. Symptoms are a distended stomach, trying to vomit & only bringing up a little water, panting, pacing the floor. The dog MUST get to a vet immediately - that means get the keys & get into the car. No waiting until the vet opens to save the emergency room fee.

Symptoms of overheating are more difficult to assess. You should look for excessive panting and slowing down - especially in normally energetic dogs. Always carry cold water for your dog in hot conditions & give him water at frequent intervals. Stumbling is a big warning sign - get into the shade & pour or squirt the cold water on the stomach/groin area and between the pads of the feet. Call somebody to pick you up (you do carry a cell phone, right?) and when you get home, immerse Fido into a tub of cold water & call your vet.

Sorry for the long post - I'm a little rabid (pun intended) about this. I see so many people in Tucson running their dogs in the heat - it makes me nuts.